Question

我在使用asp.net core 2 api项目中具有多个上下文的实体框架构建通用存储库时迷路了。

我需要的是将我的存储库注入控制器，而不知道它使用的是哪个上下文。

DbContext

public interface IDbContext
{
}

public interface IBlogContext : IDbContext
{
}

public interface IBlogLogContext : IDbContext
{
}

存储库

public class EfRepository<TEntity> : IRepository<TEntity> where TEntity : class, IEntity
{
    private readonly IDbContext _context;
    private readonly DbSet<TEntity> _dbSet;

    public EfRepository(IDbContext context)
    {
        _context = context;
        _dbSet = _context.Set<TEntity>();
    }
    /* other stuff */
}

启动

public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext<BlogContext>(options =>
        {

options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))
            .UseLoggerFactory(_logger);
        });
        services.AddDbContext<BlogLogContext>(options =>
        {
            options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"));
        });
        services.AddScoped(typeof(IRepository<>), typeof(EfRepository<>));

        services.AddScoped<IBlogContext, BlogContext>();
        services.AddScoped<IBlogLogContext, BlogLogContext>();

        services.AddUnitOfWork<BlogContext, BlogLogContext>();

    }

控制器

public class UserController : Controller
{
    private readonly IRepository<User> _repository;
    private readonly IAuthorService _authorService;
    private readonly ILogger<UserController> _logger;

    public UserController(IRepository<User> repository, IAuthorService authorService, ILogger<UserController> logger)
    {
        _repository = repository;
        _authorService = authorService;
        _logger = logger;
    }
}

当我在控制器构造函数中注入IRepository<User>时，.net核心DI如何解析User是BlogContext的实体，因此IDbContext应该是BlogContext在我的EfRepository实现中？

Answer 1

英语不好，希望我能为您

我用DbContext通用参数定义了我的EfRepository：

 public class EfRepository<TDbContext, TEntity> : IRepository<TEntity>
    where TDbContext : DbContext
    where TEntity : class, IEntity
{
    public EfRepository(IDbContextProvider<TDbContext> dbContextProvider)
    {
    }
}

并获得像这样的DbContext-Entity信息：

//EntityTypeInfo is a class has EntityType & DeclaringType props
private IList<EntityTypeInfo> GetEntityTypeInfos()
{
    var result = new List<EntityTypeInfo>();
    var dbContextTypes = this.GetType().Assembly.GetTypes().Where(t => (typeof(DbContext).IsAssignableFrom(t)));
    foreach (var dbContextType in dbContextTypes)
    {
        result.AddRange(
            from property in dbContextType.GetProperties(BindingFlags.Public | BindingFlags.Instance)
            where
                Common.IsAssignableToGenericType(property.PropertyType, typeof(DbSet<>)) &&
                Common.IsAssignableToGenericType(property.PropertyType.GenericTypeArguments[0], typeof(IEntity))
            select new EntityTypeInfo(
                property.PropertyType.GenericTypeArguments[0],
                property.DeclaringType
                );
    }
    return result;
}

因此，我可以使用EntityTypeInfo列表添加相关服务：

var entityTypeInfos = GetEntityTypeInfos();
foreach (var entityTypeInfo in entityTypeInfos)
{
    //
    //Add IDbContextProvider and DbContext services Here
    //

    //Add IRepository services like this
    var repositoryInterface =typeof(IRepository<>);
    var repositoryImplementation =typeof(EfRepository<,>);

    var genericRepositoryType = repositoryInterface.MakeGenericType(entityTypeInfo.EntityType);
    if (!Common.IocHasRegister(genericRepositoryType))
    {
        var implRepositoryType = repositoryImplementation.MakeGenericType(entityTypeInfo.DeclaringType, entityTypeInfo.EntityType);

        services.AddScoped(genericRepositoryType, implRepositoryType);
    }
}

使用通用dbContext获取通用存储库（多个dbContext）

DbContext

存储库

启动

控制器

1 个答案: